CN102866453B - Light guide plate, suface light source device and transmission image display device - Google Patents
Light guide plate, suface light source device and transmission image display device Download PDFInfo
- Publication number
- CN102866453B CN102866453B CN201210229518.3A CN201210229518A CN102866453B CN 102866453 B CN102866453 B CN 102866453B CN 201210229518 A CN201210229518 A CN 201210229518A CN 102866453 B CN102866453 B CN 102866453B
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- China
- Prior art keywords
- light
- guide plate
- lens unit
- light guide
- axle
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Classifications
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/0001—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems
- G02B6/0011—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems the light guides being planar or of plate-like form
- G02B6/0033—Means for improving the coupling-out of light from the light guide
- G02B6/0035—Means for improving the coupling-out of light from the light guide provided on the surface of the light guide or in the bulk of it
- G02B6/0038—Linear indentations or grooves, e.g. arc-shaped grooves or meandering grooves, extending over the full length or width of the light guide
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B3/00—Simple or compound lenses
- G02B3/0006—Arrays
- G02B3/0037—Arrays characterized by the distribution or form of lenses
- G02B3/005—Arrays characterized by the distribution or form of lenses arranged along a single direction only, e.g. lenticular sheets
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/0001—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems
- G02B6/0011—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems the light guides being planar or of plate-like form
- G02B6/0033—Means for improving the coupling-out of light from the light guide
- G02B6/0035—Means for improving the coupling-out of light from the light guide provided on the surface of the light guide or in the bulk of it
- G02B6/004—Scattering dots or dot-like elements, e.g. microbeads, scattering particles, nanoparticles
- G02B6/0043—Scattering dots or dot-like elements, e.g. microbeads, scattering particles, nanoparticles provided on the surface of the light guide
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/0001—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems
- G02B6/0011—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems the light guides being planar or of plate-like form
- G02B6/0033—Means for improving the coupling-out of light from the light guide
- G02B6/0058—Means for improving the coupling-out of light from the light guide varying in density, size, shape or depth along the light guide
- G02B6/0061—Means for improving the coupling-out of light from the light guide varying in density, size, shape or depth along the light guide to provide homogeneous light output intensity
-
- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on liquid crystals, e.g. single liquid crystal display cells
- G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
- G02F1/1333—Constructional arrangements; Manufacturing methods
- G02F1/1335—Structural association of cells with optical devices, e.g. polarisers or reflectors
Abstract
A kind of light guide plate, suface light source device and transmission image display device are provided.This light guide plate (40) receives and incides the light on light guide plate (40) by light-entering surface (40a) and so that this light is launched from light output surface (40b).Light guide plate (40) has the multiple lens units (43) on light output surface, and each described lens unit (43) extends to the surface (41d) contrary with light-entering surface from light-entering surface.The plurality of lens unit is embarked on journey along the direction arrangement orthogonal with bearing of trend.In the lens unit cross section orthogonal with bearing of trend, set the axle that u axle is two ends through lens unit, v axle is the axle at simultaneously center through two ends (43a) u axle between orthogonal with u axle, waIt is the length along u axle for the lens unit, the shape of lens unit is by 0.475wa≤u≤0.475waIn the range of meet 0.95v0(u)≤v(u)≤1.05v0U the v (u) of () represents, v0U () meets following formula (1)：[formula 1]Wherein haAnd kaFor meeting 0.4≤ha/wa≤0.7、‑0.75≤ka＜ 0 and 1≤ka+4×(ha/waThe constant of)≤2.
Description
Technical field
The present invention relates to light guide plate, suface light source device and transmission image display device.
Background technology
Generally, transmission image display device (such as liquid crystal indicator) has and is arranged in transmission type image display unit
The suface light source device of the rear side of (such as display panels), this suface light source device is used for showing list to transmission type image
Unit provides backlight.As such surface source of light it is known that the edge-light type suface light source device that has (see, for example, non-patent
Document：SASAKI Shinya, " 3D support rekindles competition for higher resolution
TVs ", NIKKEI ELECTRONICS, August 23,2010issue, pp.83-93.).Edge-light type suface light source device bag
Include the light guide plate of transmission light and be arranged in light guide plate side for providing the light source of light to the side of light guide plate.
As light source, from the viewpoint of low-power consumption, not using hydrargyrum etc., recently using point source, such as light emitting diode.
When deployed, multiple point sources to be arranged generally along the direction of the side extension of light guide plate.In such a configuration, open and
Close the specified point source in the plurality of point source such that it is able to realize so-called local dimming and scanning.This improves right
Than degree and reduce the generation of after image and (see, for example, non-patent literature：SASAKI Shinya, " 3D support rekindles
Competition for higher resolution TVs ", NIKKEI ELECTRONICS, August 23,
2010issue, pp.83-93.).
Content of the invention
However, from point source transmitting light tend to becoming wider with its point of distance light emission, thus it may happen that
Crosstalk.
Therefore it is an object of the present invention to provide the light guide plate of crosstalk, suface light source device and transmission can be suppressed
Type image display device.
According to the light guide plate of the present invention be a kind of receive by light-entering surface light incident thereon and make light from enter light
The light guide plate that the light output surface that surface is intersected is launched.Had according to the light guide plate of the present invention be arranged on many on light output surface
Individual lens unit, each lens unit extends to the surface contrary with light-entering surface from light-entering surface.The plurality of lens unit
It is arranged in line along the direction orthogonal with the bearing of trend of lens unit.Each lens unit in the plurality of lens unit
In the cross section orthogonal with bearing of trend, set the axle that u axle is two ends through lens unit, v axle is orthogonal with u axle same
When on u axle the center between two ends axle, and waIt is the length along u axle for the lens unit, each lens unit
Shape of cross section by -0.475 × wa≤u≤0.475×waIn the range of meet following formula (1) v (u) represent：
[formula 1]
0.95v0(u)≤v(u)≤1.05v0(u) (1)
Wherein v0U () meets following formula (2)：
[formula 2]
Wherein haAnd kaIt is constant, meet：
0.4≤ha/wa≤ 0.7,
-0.75≤ka＜ 0.00, and
1.00≤ka+4.00×(ha/wa)≤2.00.
In the structure shown here, on light output surface as above, formation has the shape of cross section represented by formula (1)
Multiple lens units, the light (if so) thus inciding on the light-entering surface of light guide plate may be in the extension of lens unit
Side upwardly propagates.Therefore, when light propagates through light guide plate from its in-position it is suppressed that the broadening, thus, it is possible to subtract of light
Few crosstalk.
In the light guide plate according to the present invention, haCan be satisfaction 0.4≤ha/wa≤ 0.6 constant.In this case,
Its width of the aspect ratio of each lens unit is more suppressed.This makes easily to be formed when by molded light guide plates such as such as resins
Lens unit.
In the light guide plate according to the present invention, kaCan be to meet -0.75≤ka≤ -0.25 constant.Which suppress each
The leading section (leading end part) of lens unit comes to a point.As a result, when by molded light guide plates such as such as resins, Neng Gourong
Change places formation lens unit.
Above-mentioned light guide plate is included and for providing light to the light-entering surface of light guide plate according to the suface light source device of the present invention
Multiple point sources.
In this suface light source device, as described above, formed to have on the light output surface of light guide plate being represented by formula (1)
Multiple lens units of shape of cross section.Therefore, light from the light-entering surface that point source incides light guide plate is (if having
Words) when propagating through light guide plate from its in-position be suppressed broaden.As a result, more substantial light can be in the entrance position of light
Put front to propagate, thus, it is possible to reduce crosstalk.
Included according to the transmission image display device of the present invention：Above-mentioned light guide plate；For the light-entering surface to light guide plate
Multiple point sources of light are provided；And it is saturating for the display image in the optical illumination launched from the light output surface of light guide plate
Emitting image-display units.
In this transmission image display device, as described above, formed on the light output surface of light guide plate having by formula (1)
Multiple lens units of represented shape of cross section.Therefore, the light from the light-entering surface that point source incides light guide plate is (false
It is suppressed when propagating through light guide plate from its in-position if any) and broaden.As a result, more substantial light can be in light
Propagate in front of in-position, thus, it is possible to reduce crosstalk.Therefore, it is possible to be more effectively carried out local dimming and scanning.
The present invention can provide light guide plate, suface light source device and the transmission image display device that can suppress crosstalk.
Brief description
Fig. 1 is the substantially knot of the transmission image display device illustrating the embodiment using the light guide plate according to the present invention
The schematic diagram of structure；
Fig. 2 is the axonometric chart schematically showing the structure of light guide plate of diagram in Fig. 1；
Fig. 3 is the figure of an example of the shape of cross section illustrating the lens unit in light guide plate；
Fig. 4 is the figure for analogue model is described；
Fig. 5 (a) is the figure illustrating when forming lens unit time spread state, and Fig. 5 (b) is to illustrate not forming lens
The figure of unit time spread state；
Fig. 6 is the figure for evaluation number is described, this evaluation number is used for evaluating the effect of lens unit by illumination；
Fig. 7 is to describe evaluation number with respect to ha/waAnd kaRelation figure；
Fig. 8 is the h illustrating evaluation number with limiting the adoptable shape of cross section of lens unita/waAnd kaBetween relation
Chart；With
Fig. 9 is the figure of another example illustrating the position relationship between light source cell and light guide plate.
Specific embodiment
Hereinafter, explain embodiment of the present invention with reference to the accompanying drawings.In the description of the drawings, identical or wait
To be represented with same reference numerals with part, omit repetition thereof simultaneously.Dimension scale in accompanying drawing not necessarily with
Illustrate is consistent.In explanation, represent direction term, such as "up" and "down", be with reference to the accompanying drawings shown in state for
Conveniently use.
Fig. 1 is to illustrate to adopt the big of the transmission image display device of an embodiment of the light guide plate according to the present invention
Cause the schematic diagram of structure.Fig. 1 schematically shows the cross-sectional structure of transmission image display device 10 in an exploded manner.Thoroughly
Emitting image display device 10 can be advantageously used for the display device for mobile phone and multiple electronic installation, or as electricity
View apparatus.
Transmission image display device 10 includes transmission type image display unit 20 and suface light source device 30, this surface light
Source device 30 is used for the surface light that output is supplied to transmission type image display unit 20.Hereinafter, for convenience of explanation, phase
The transmission image display device 20 of direction to arrange to(for) surface source of light 30 will be referred to as Z-direction, as shown in Figure 1.With Z axis
The orthogonal both direction in direction is referred to as X-direction and Y direction respectively, and X-direction and Y direction are orthogonal.
When the surface optical illumination launched from light guide plate 40, transmission type image display unit 20 display image.Transmission
One example of type image-display units 20 is display panels, such as polarizer layer pressing plate, and wherein line style polaroid is arranged in
The both sides of liquid crystal cells.In this case, transmission image display device 10 is liquid crystal indicator (or LCD TV).Close
In liquid crystal cells and polaroid, can be using used in traditional transmission image display device (such as liquid crystal indicator)
Those.The example of liquid crystal cells includes TFT (TFT) type liquid crystal cells and STN Super TN (STN) type liquid crystal
Unit.The example of the shape of the transmission type image display unit 20 illustrating as plane (seeing in the Z-axis direction) includes rectangle
Shape and square shape.The size of transmission type image display unit 20 is fitted according to the size of transmission image display device 10
Local determination.
Suface light source device 30 is the edge-light type back light unit for providing backlight to transmission type image display unit 20.
Suface light source device 30 includes light guide plate 40 and is arranged in the light source cell 50 on the light-entering surface 40a side of light guide plate 40.
Light source cell 50 has the multiple point sources 51 being arranged to line (along the Y direction arrangement of Fig. 1).The one of point source 51
Individual example is light emitting diode.Between point source 51 adjacent one another are, the distance of (in the Y-axis direction) is usually 5mm to 30mm.
In order that light is incident on light guide plate 40 effectively, light source cell 50 can be furnished with the reflector as reflecting member, its setting
In the opposite side of light guide plate 40, for reflected light.
Suface light source device 30 can be coordinated in the side contrary with transmission type image display unit 20 of light guide plate 40
Reflector element 60.Reflector element 60 is used for making the light shining reflector element 60 from light guide plate 40 be again incident on light guide plate 40
On.Reflector element 60 can be reflector plate, as shown in Figure 1.Reflector element 60 can be the surface source of light dress of accommodating light guide plate 40
Put the mirror finish bottom surface (mirror-finished bottom face) of 30 housings.
Now with reference to Fig. 1 and Fig. 2, light guide plate 40 to be described.Fig. 2 is the vertical of an example of the light guide plate 40 shown in Fig. 1
Body figure.
Light guide plate 40 receives, by the light-entering surface 40a relative with point source 51, the light inciding on light guide plate 40, and makes
This light is launched from light output surface 40b as surface light.The shape being shown as the light guide plate 40 of plane is, for example, rectangle, but
Can be square.(transmission type image shows be sized to and the screen size of transmission image display device of light guide plate 40
Show the size of unit 20) consistent.One example of the size of light guide plate 40 is at least 250mm × 440mm, but is no more than
1020mm×1800mm.
Light guide plate 40 has planar body 41.The shape being shown as the body 41 of plane is, for example, rectangle, but also may be used
Think square.Body 41 is made up of light transmissive material.Constitute the refractive index for example, 1.46 to 1.62 of the material of body 41.Constitute
The example of the material of body 41 includes transparent resin material, for example, with polymethyl methacrylate (PPMA) resin as representative
(methyl) acrylic resin, polystyrene resins, cyclic olefin resins and polymethylpentene.In these exemplary resins, excellent
Choosing is methyl (acrylic acid) resin, that is, comprise methymethacrylate as the resin of their major polymer component, especially
It is such when from the viewpoint of transparency and thermostability.
Body 41 has：Front 41a as the first interarea；The back side as second interarea contrary with front 41a
41b；And four side 41c, 41d, 41e and 41fs orthogonal with least one of front 41a and back side 41b.In Fig. 1 institute
In the pattern shown, front 41a is used as the light output surface 40b of light guide plate 40, and the side in four sides 41c, 41d, 41e and 41f
Face 41c incides on light-entering surface 40a as light-entering surface 40a, the light from light source cell 50.Incide light-entering surface 40a
On light propagate through body 41 and be totally reflected wherein simultaneously.Side 41c, 41d, 41e and 41f can be mirror finish tables
Face.However, side 41c, 41d, 41e and 41f could be formed with otch etc., for light guide plate 40 is attached to installation surface light source
The housing of device 30 grade.Light-entering surface 40a can be formed further with the lens for converging light or diverging light.
Back side 41b can be generally mirror finished surface.However, after back side 41b can stand roughening (for example embossing)
Rough surface, the scope of this purport without departing from the present invention.
Light guide plate 40 also has the multiple pips 42 as reflector element overleaf on 41b side for the setting.Pip 42
It is such as chalk point but it is also possible to be lenticule.Under conditions of different from total reflection condition, each pip 42 will be from entering light
The light that surface 40a entered and propagated through body 42 reflexes to light output surface 40b.Adjust the arrangement pattern of multiple pips 42,
So that effectively launching uniform surface light from light output surface 40b.Pip 42 adjacent one another are can be separated from each other or that
This connects.Merely just by pip 42, reflector element is illustrated, reflector element can be any article, as long as
The light being guided through body 41 can be reflexed to light output surface 40b under conditions of different from total reflection condition by it.
The front 41a of body 41, i.e. the light output surface 40b of light guide plate 40, are formed with multiple lens units 43.Fig. 2 illustrates
Lens unit 43 quantity be for the ease of represent define multiple lens units 43.The quantity of lens unit 43 can basis
Spacing of the size of light guide plate 40 and lens unit 43 etc. determines, it depends on the size of transmission image display device 10 and becomes
Change.Each lens unit 43 from the side 41c as light-entering surface 40a extend to the side 41d relative with side 41c (
In the X-direction of Fig. 1).That is, each lens unit 43 is ridge.When side 41c is the flat table being orthogonal to back side 41b
During face, lens unit 43 extends along perpendicular to the direction of side 41c.Multiple lens units 43 along with the prolonging of lens unit 43
Stretch the orthogonal direction arrangement in direction to embark on journey.On the bearing of trend of lens unit 43, lens unit 43 orthogonal with bearing of trend
Cross section there is basically identical shape.Two lens units 43 and 43 adjacent one another are have the phase in X-direction
With the end 43a at position.
Fig. 3 is the figure of an example illustrating the lens unit shape of cross section orthogonal with the bearing of trend of lens unit.
In figure 3, by the direction orthogonal with the bearing of trend of lens unit 43 to be arranged u-v coordinate system as u axle.In this u-v
In coordinate system, the shape of cross section of lens unit 43 has two end 43a and 43a on u axle.In this u-v coordinate system,
V axle is through the center between two end 43a and 43a on u axle.In pattern shown in Fig. 1 and Fig. 2, u direction corresponds to
Y direction, v direction corresponds to Z-direction.
In u-v coordinate system, the shape of cross section of lens unit 43 is represented by the v (u) meeting following formula (3)：
[formula 3]
0.95v0(u)≤v(u)≤1.05v0(u) (3)
Wherein v0U () meets following formula (4)：
[formula 4]
In formula (4), waIt is width on u direction for the lens unit 43.Generally, width waLess than point light adjacent one another are
The distance between source 51.Width waFor example, 50 μm to 2000 μm it is therefore preferable to 100 μm to 1000 μm, more preferably 200 μm
To 800 μm.Herein, haCorresponding to the maximum height between two end 43a and 43a of lens unit 43.In in formula (4), ka
It is to represent the parameter of acutance (acuteness) (shape) of the conical section represented by formula (4) and represent lens unit 43
The acutance of leading section.Specifically, kaIt is a kind of parameter as follows：Work as kaWhen being respectively 0,1 and -1, the external shape of lens 43 is changed into
Parabola, prismatic and half elliptic.
It is contemplated that the shape of cross section of lens unit 43, maximum height h in formula (4)aIt is to meet following formula with acutance ka
(5) to the constant of formula (7).In other words, lens unit 43 has based on by maximum height ha, width waWith acutance kaLimit
The shape of cross section of the curve of formula (4), wherein maximum height ha, width waWith acutance kaIt is chosen as meeting formula (5) to formula (7)：
[formula 5]
0.4≤ha/wa≤0.7 (5)
[formula 6]
-0.75≤ka＜ 0.00 (6)
[formula 7]
1.00≤ka+4.00×(ha/wa)≤2.00 (7)
In formula (5) to formula (7), ha/waDepth-width ratio corresponding to lens unit 43.Hereinafter, ha/waAlso can be claimed
Make depth-width ratio.
Fig. 3 illustrates an example of the shape of cross section of lens unit in v=v0Situation when (u).Specifically, Fig. 3 shows
The shape of cross section going out represents wherein depth-width ratio (ha/wa) and acutance kaIt is respectively 0.40 and -0.4 v0The example of (u).As Fig. 3
Shown, lens unit 43 can have profile axisymmetric with regard to v.In order to show the condition that lens unit 43 is met, Fig. 3 is also
Illustrated by 0.95v with dotted line and single dotted broken line respectively0(u) and 1.05v0U profile that () represents.Work as v0U () is with respect to given width
Degree waDuring determining, the shape of cross section of lens unit 43 only needs to meet formula (3) and can be therefore through by 0.95v0(u)
And 1.05v0The profile in the region between u respective profile that () represents.Lens unit 43 also has following external shape：In lens
The angle being formed between the front 41a (u axle) of the tangent plane of unit 43 and body 41 from two end 43a of lens unit 43 and
Monotone decreasing at forward end 43b at 43a.
Preceding description supposes that the shape of cross section of lens unit 43 is represented by the v (u) meeting formula (3).However, in view of saturating
Foozle near two end 43a and 43a of mirror unit 43 etc., if the shape of cross section of lens unit 43 be by-
0.475wa≤u≤0.475waIn the range of meet the v (u) of formula (3) and be sufficient to represent.
The plurality of lens unit 43 has essentially identical shape of cross section.However, the plurality of lens unit 43 is each
From shape of cross section can change, as long as this shape of cross section meets formula (3).
Without departing from the spirit and scope of the invention, the light guide plate 40 being constructed so as to for example can comprise additive, example
As UV absorbent, antistatic agent, antioxidant, processing stabilizers, fire retardant, lubricant and light dissipate body.Light guide plate
40 (especially bodies 41) can have the multiple structure replacing single layer structure.In this embodiment, there is lens unit 43
The thickness of light guide plate 40 identical with the thickness of body 41.The thickness of body 41, that is, the summit of lens unit 43 and back side 41b it
Between distance, usually 0.5mm to 8mm is it is therefore preferable to 1mm to 6mm, more preferably 1.5mm to 4mm.
Light guide plate 40 can form reflector element (in Fig. 1 by making body 41 and then on the back side 41b of body 41
Pip 42) manufacturing.Body 41 by such as extrusion, casting, injection mo(u)lding or can carry out machining from flat board and makes
Become.Body 41 can be made by onboard forming lens unit 43 by photopolymer etc..Specifically, when by for example extruding
During forming body 41, first pass through extrusion manufactured Board.Subsequently, it is formed with corresponding to the plurality of lens unit 43 using having
Transmission mould periphery forming rolls, this transmission mould is delivered to the front of plate, with manufacture there is the plurality of lens unit 43
Body 41.Lens unit 43 can be formed onboard by above-mentioned photopolymer or machining.As reflector element
Pip 42 to be formed by such as ink jet printing, silk screen printing or Laser Processing.Always do not need after making body 41
Just form reflector element.Light guide plate 40 can be integrally formed body 41 and reflector element by such as injection mo(u)lding and directly make
Make.
In the light guide plate 40 being constructed so as to, from the light of point source 51 transmitting, light guide plate 40 is entered by light-entering surface 40a.
The light entering light guide plate 40 travels to the side 41d relative with light-entering surface 40a and is totally reflected simultaneously；When irradiating in the air
During to pip 42, light random reflected in this place under conditions of different from total reflection condition, to launch from light output surface 40b
Go.Due to being guided through a part of light of light guide plate 40 from light output surface 40b out it is possible to send out from light output surface 40b
Project surface light.
Because the light output surface 40b of light guide plate 40 is formed with multiple lens units 43, (each lens unit 43 has full
The shape of cross section of sufficient formula (3) simultaneously extends along the X-direction in Fig. 1 and Fig. 2), so the light entering from point source 51 is assembled
Bearing of trend (X-direction in Fig. 1 and Fig. 2) to lens unit 43.Therefore, light may be along the bearing of trend of lens unit 43
Propagate.Which reduce the crosstalk between the corresponding light component of point source 51 and 51 transmitting adjacent one another are, thus adopt leaded light
The transmission image display device 10 of plate 40 can more efficiently carry out local dimming, scanning etc..Similarly, guide-lighting using including
The transmission image display device 10 of the suface light source device 30 of plate 40 can more efficiently carry out local dimming and scanning etc..Knot
Really, the transmission image display device 10 including light guide plate 40 can improve contrast and reduce after image, thus improve its figure
As quality.
In depth-width ratio (ha/wa) in the case of 0.7 or less, lens unit 43 becomes more flat, be therefore easier to mould.
For example, when by the transmission mould being used for being formed lens unit 43 is transferred to plate to form lens unit 43, for example, this raising
The transport of transmission mould.For this point, depth-width ratio (ha/wa) more preferably at least 0.4 but no more than 0.6.
When acutance kaDuring for 0 or bigger, the leading section of lens unit 43 becomes to be excessively sharp；And work as acutance kaIt is less than -0.75
When, lens unit 43 tends to increasing the angle of its shirt rim, thus becomes increasingly difficult to mould.
By comparison, there is acutance k meeting formula (6)aLens unit 43 be easier mould.When by using transmitting mould
When forming lens unit 43, for example, the transport of transmission mould improves, as in the situation of depth-width ratio.For this point, acutance ka
It is more preferably at least -0.75 but be not more than -0.25.
Now, with reference to analog result, following facts will be described：When light guide plate 40 is furnished with lens unit 43, from point source
51 light is easier to propagate on the bearing of trend of lens unit 43.
Fig. 4 is the figure for analogue model is described.Optical sheet 70 is adopted as light guide plate, when being shown as plane in simulation
When, optical sheet 70 has rectangular shape, as shown in Figure 4.In simulations, at the back side of optical sheet 70 (with optical sheet 70 just
The contrary surface of face 70a) on do not form reflector element.In the shape being shown as plane shown in Fig. 4, optical sheet 70 is longer
Length at side and shorter edge is respectively 400mm and 200mm.Hereinafter, for convenience of explanation, longer sides direction and shorter edge
Direction is referred to as x-axis direction and y-axis direction respectively, as shown in Figure 4.The refractive index of optical sheet 70 is 1.49.
One point source 71 is arranged as relative with the side 70b of optical sheet 70.In the structure shown here, side 70b corresponds to and makees
Light-entering surface 40a for the optical sheet 70 of light guide plate.The distance between point source 71 and side 70b are 0.2mm.In simulations,
Point source 71 is configured with ± 68 ° of distribution of orientations and has the illumination region producing a diameter of 1mm on the 70b of side
The characteristics of luminescence.
Three sides of other in addition to the side 70b relative with point source 71 are all assumed absorbing surface.In optical sheet
In 70, adjust the shape of the front 70a as light output surface, to execute simulation 1 and simulation 2.Fig. 4 is provided with for schematically showing
Go out the shade of the light from point source 71 transmitting.
In simulations 1 and simulation 2 in, the thickness of optical sheet 70 is 4mm.When being formed on the 70a of front in lens unit 43
During with being not formed on the 70a of front, the thickness of optical sheet 70 is assumed to the summit of lens unit 43 and the back of the body of optical sheet 70 respectively
The distance between face and the distance between front 70a and the back side.
Simulation 1
In simulation 1, the light in research scenario described below is propagated：Situation (the simulation of lens unit 43 is formed on the 70a of front
1a)；And the situation of lens unit 43 is not formed on the 70a of front, i.e. front 70a is the situation (simulation 1b) of flat surfaces.
In simulation 1a, multiple lens units 43 are arranged along the x-axis direction on the 70a of front and are embarked on journey, each lens unit
43 extend (perpendicular to side 70b) all along the y-axis direction.The plurality of lens unit 43 is arranged in the direction of the x axis each other
Very close to each other.The width w of lens unit 43a, i.e. lenticular spacing, is 0.5mm.The shape of cross section of lens unit 43 is by formula (4)
Represent.I.e., it is assumed that representing that the v (u) of shape of cross section is equal to v0(u).U direction in formula (4) and v direction correspond respectively to Fig. 4
The x-axis direction illustrating and y-axis direction.In the lens unit 43 being configured with simulation 1a, depth-width ratio (ha/wa) and acutance kaRespectively
It is assumed to 0.4 and -0.4.The shape of this lens unit 43 meets formula (5) to formula (7).
Fig. 5 (a) is the figure illustrating to simulate the result of 1a, and Fig. 5 (b) is the figure illustrating to simulate the result of 1b.Except front 70a's
Shape is different outer, and simulation 1a is identical with the condition of simulation 1b.When be compared to each other Fig. 5 (a) and during Fig. 5 (b) it will be understood that with not
The situation (situation of Fig. 5 (b)) forming lens unit 43 is compared, and is being formed with the lens unit 43 meeting formula (5) to formula (7)
In situation (situation of Fig. 5 (a)), more light converge to the front of the light incoming position on the 70b of side.That is, it is provided with lens
Unit 43 can suppress light to broaden.Therefore, it is possible to effectively carry out local dimming etc..
Simulation 2
In simulation 2, multiple lens units 43 are arranged along the x-axis direction on the 70a of front and are embarked on journey, each lens unit 43
All extend along the y-axis direction.The plurality of lens unit 43 is arranged as very close to each other each other in the direction of the x axis.Lens unit
43 width wa, i.e. lenticular spacing, is 0.5mm.As in simulation 1a, the shape of cross section of lens unit 43 is by formula (4)
Represent.In simulation 2, change depth-width ratio (ha/wa) and acutance kaSo that changing the transversal of lens unit 43 in many ways
Face shape, and calculate the illumination on the side relative with side 70b of side.
Illumination calculates by the following method.Virtual surface 72 (surface being represented by single dotted broken line in the diagram) is placed
In the position for 0.01mm from side.It is assumed that virtual surface 72 is divided into 100 × 1 grids (grid of 4mm), simultaneously at each
In grid install optical pickup apparatus, using the quantity of the light beam being received by each optical pickup apparatus as light illumination.
The maximum of the illumination in each illumination virtual surface 72 is normalized, i.e. when the maximum of illumination is adopted
When using 100%, each illumination is marked and drawed with respect to the position of this maximum with each illumination, to generate Illumination Distribution.Then, such as
Shown in Fig. 6,50% Illumination Distribution width t is changed into as evaluation number using illumination.Fig. 6 is for evaluation number is described
Figure, this evaluation number is used for evaluating the effect of lens unit 43 by illumination.Abscissa in Fig. 6 and vertical coordinate represent respectively
Illumination behind position and normalization.As shown in fig. 6, the Illumination Distribution width as evaluation number is to present 100% illumination
Position both sides in the width of side and corresponding to the half width at half maximum.
Fig. 7 is the chart marked and drawed for the evaluation number of lens unit shape being limited by depth-width ratio and acutance.In Fig. 7
Abscissa and vertical coordinate represent depth-width ratio (h respectivelya/wa) and acutance ka.Each value in Fig. 7 all represents at half maximum
Half-width value (the irradiation dispersion of distribution) t, i.e. evaluation number, unit is mm.The line I being represented by single dotted broken line in Fig. 7 represents ka=-
4.00(ha/wa)+2.00；The line II being represented by single dotted broken line in Fig. 7 represents ka=-4.00 (ha/wa)+1.00；Solid line in Fig. 7
Represent the border in the region being limited by formula (5) to formula (7).But the k in formula (6)aLess than 0, diagram for convenience, in kaAt=0
Line partly represented with solid line.
In the figure 7, Illumination Distribution width t be value during 24mm or less all by addition underscore, simultaneously in described region
Solid-line boundary on and in region, Illumination Distribution width t be 24mm or less plot point represented by white box.?
Show in Fig. 8 meet formula (5) to formula (7) corresponding to the plot point being represented by white box depth-width ratio (ha/wa) and acutance
kaCombination and when using evaluation number t obtaining during by these limited lens units 43 of combination.Fig. 8 is to illustrate to evaluate
Index and the depth-width ratio (h limiting the adoptable shape of cross section of lens unita/wa) and acutance kaBetween relation chart.
As shown in Figure 7 and Figure 8, when be formed with light output surface 40b meet formula (5) to formula (7) lens unit 43 when,
Evaluation number t can be 24mm or less.
In simulation 2, similarly assess the situation that lens unit 43 is not formed on the 70a of front, for comparing.At this
Under situation, the value of evaluation number t is 149.2mm.
Therefore can be seen that to be formed on the 70a of front from the result of simulation 2 and meet formula (5) to the lens unit 43 of formula (7)
Evaluation number t can be greatly reduced, i.e. suppression light broadens so that greater number of light can be in the extension side of lens unit 43
To propagation.
As shown in the result of above-mentioned simulation 1 and simulation 2, make to be formed the shape of cross section satisfaction of each on light output surface 40b
Light from point source 51 can be converged to prolonging of lens unit 43 by the light guide plate 40 of the lens unit 43 to formula (7) for the formula (5)
Stretch direction to be propagated.Which suppress above-mentioned crosstalk, thus, it is possible to efficiently perform local dimming and scanning.
Although before it is stated that embodiment of the present invention, the invention is not restricted to the embodiment above, but permissible
Modify in every way in the case of the scope without departing from present subject matter.Mode shown in Fig. 1 adopts side 41c to make
For light-entering surface, simultaneously in side 41c arranged alongside light source cell 50 (point source 51).However, light source cell 50 can be arranged
On the side 41e being adopted as light-entering surface or side 41f side.In this case, each is along the Y-axis in Fig. 1 and Fig. 2
Multiple lens units 43 that direction extends are along X-direction arrangement in a row.Such as can adopt using side 41d as light-entering surface
Side 41c is the same as the situation of light-entering surface.Only there is in mode shown in Fig. 1 a light-entering surface.However, light guide plate
Can have two light-entering surfaces.In this case, a side and the side relative with this side are as light-entering surface.Example
As, as shown in figure 9, can be in the corresponding light source cell of the arranged alongside of side 41c and side 41d 50 so that side 41c and side
Face 41d is as light-entering surface.Fig. 9 is the figure illustrating this alternate examples position relationship between light source cell and light guide plate.
Fig. 9 is the figure of light guide plate 40 in terms of light output surface 40b side.When in side 41c and the corresponding light source cell of side 41d side placement
When 50, the mode of lens unit 43 such as Fig. 1 and Fig. 2 is arranged.In another embodiment, on the side of side 41e and side 41f
Side arranges respective light source cell 50 so that side 41e and side 41f can be used as light-entering surface.In this case, lens list
Unit 43 arrangement with using one of side 41e and side 41f side as in the case of light-entering surface to lens unit 43
Arrangement identical.
The embodiment above shows that the respective end of adjacent one another are two lens unit 43 and 43 is located in X-direction
Identical position.However, without departing from the spirit and scope of the invention, described adjacent two lens units 43 and 43 are permissible
It is provided with flat.
Claims (5)
1. a kind of light guide plate, described light guide plate is used for reception and incides the light on described light guide plate by light-entering surface and make described
Light is launched from the light output surface being intersected with described light-entering surface,
Described light guide plate has the multiple lens units being arranged on described light output surface, each described lens unit from described enter
Optical surface extends to the surface contrary with described light-entering surface；
Wherein said multiple lens unit is embarked on journey along the direction arrangement orthogonal with the bearing of trend of described lens unit；With
Wherein, in the cross section orthogonal with described bearing of trend of each lens unit in the plurality of lens unit, if
Determine the axle of two ends that u axle is through described lens unit, v axle is simultaneously passes through on described u axle orthogonal with described u axle
The axle at the center between described two ends, and waIt is the length along described u axle for the described lens unit, each lens unit
Shape of cross section by -0.475 × wa≤u≤0.475×waIn the range of meet following formula (1) v (u) represent：
[formula 1]
0.95v0(u)≤v(u)≤1.05v0(u) (1)
Wherein said v0U () meets following formula (2)：
[formula 2]
Wherein said haWith described kaIt is constant, meet：
0.4≤ha/wa≤ 0.7,
-0.75≤ka＜ 0.00, and
1.00≤ka+4.00×(ha/wa)≤2.00.
2. light guide plate according to claim 1, wherein haFor meeting 0.4≤ha/wa≤ 0.6 constant.
3. light guide plate according to claim 1 and 2, wherein kaFor meeting -0.75≤ka≤ -0.25 constant.
4. a kind of suface light source device, including：
Light guide plate according to one of claims 1 to 3；With
For providing multiple point sources of light to the described light-entering surface of described light guide plate.
5. a kind of transmission image display device, including：
Light guide plate according to one of claims 1 to 3；
For providing multiple point sources of light to the described light-entering surface of described light guide plate；With
For being shown by the transmission type image of display image during from the optical illumination of the described light output surface transmitting of described light guide plate
Unit.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2011-149159 | 2011-07-05 | ||
| JP2011149159A JP5363535B2 (en) | 2011-07-05 | 2011-07-05 | Light guide plate |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN102866453A CN102866453A (en) | 2013-01-09 |
| CN102866453B true CN102866453B (en) | 2017-03-01 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201210229518.3A Expired - Fee Related CN102866453B (en) | 2011-07-05 | 2012-07-03 | Light guide plate, suface light source device and transmission image display device |
| CN2012203206657U Withdrawn - After Issue CN202720354U (en) | 2011-07-05 | 2012-07-03 | Light guide plate, surface light source device, and transmission type image display device |
Family Applications After (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2012203206657U Withdrawn - After Issue CN202720354U (en) | 2011-07-05 | 2012-07-03 | Light guide plate, surface light source device, and transmission type image display device |
Country Status (5)
| Country | Link |
|---|---|
| EP (1) | EP2544033A1 (en) |
| JP (1) | JP5363535B2 (en) |
| KR (1) | KR20130005238A (en) |
| CN (2) | CN102866453B (en) |
| TW (1) | TWI545357B (en) |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP5363535B2 (en) * | 2011-07-05 | 2013-12-11 | 住友化学株式会社 | Light guide plate |
| KR20160044145A (en) | 2014-10-14 | 2016-04-25 | 삼성디스플레이 주식회사 | Backlight unit and display apparatus having the same |
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| CN202720354U (en) * | 2011-07-05 | 2013-02-06 | 住友化学株式会社 | Light guide plate, surface light source device, and transmission type image display device |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| JP2001166303A (en) * | 1999-12-13 | 2001-06-22 | Nitto Denko Corp | Light guide plate, surface light source device and liquid crystal display device |
| JP2001166150A (en) * | 1999-12-13 | 2001-06-22 | Nitto Denko Corp | Light guide plate, surface light source device and liquid crystal display device |
| US7125131B2 (en) * | 2002-12-06 | 2006-10-24 | General Electric Company | Brightness enhancement film with improved view angle |
| JP4533728B2 (en) * | 2004-11-29 | 2010-09-01 | 株式会社 日立ディスプレイズ | Liquid crystal display |
| EP1881266A4 (en) * | 2005-03-17 | 2013-06-12 | Fujitsu Ltd | Illuminator and liquid crystal display |
| JP4506733B2 (en) * | 2005-09-05 | 2010-07-21 | ソニー株式会社 | Manufacturing method of optical film |
| JP2007206366A (en) * | 2006-02-01 | 2007-08-16 | Hitachi Displays Ltd | Liquid crystal device and its lighting unit |
| JP2007311325A (en) * | 2006-04-17 | 2007-11-29 | Citizen Electronics Co Ltd | Light guide plate and its manufacturing method, and back light unit using its light guide plate |
| KR101440498B1 (en) * | 2007-11-12 | 2014-09-18 | 삼성디스플레이 주식회사 | Light guide plate and display device having the same |
| JP5261035B2 (en) * | 2008-06-11 | 2013-08-14 | シャープ株式会社 | Backlight unit and liquid crystal display device |
| WO2011013671A1 (en) * | 2009-07-28 | 2011-02-03 | 住友化学株式会社 | Compound light-control plate, surface light source device, and transparent image display device |
| KR101613727B1 (en) * | 2009-09-23 | 2016-04-19 | 엘지디스플레이 주식회사 | Liquid crystal display |
| KR20110050270A (en) * | 2009-11-06 | 2011-05-13 | 삼성전자주식회사 | Light guide panel, back light unit and display apparatus |
| JP2012209034A (en) * | 2011-03-29 | 2012-10-25 | Sharp Corp | Light source module and liquid crystal display having this |
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2011
- 2011-07-05 JP JP2011149159A patent/JP5363535B2/en not_active Expired - Fee Related
-
2012
- 2012-07-03 CN CN201210229518.3A patent/CN102866453B/en not_active Expired - Fee Related
- 2012-07-03 CN CN2012203206657U patent/CN202720354U/en not_active Withdrawn - After Issue
- 2012-07-04 EP EP12174978A patent/EP2544033A1/en not_active Withdrawn
- 2012-07-04 KR KR1020120072689A patent/KR20130005238A/en active Search and Examination
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| CN202720354U (en) * | 2011-07-05 | 2013-02-06 | 住友化学株式会社 | Light guide plate, surface light source device, and transmission type image display device |
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| Publication number | Publication date |
|---|---|
| KR20130005238A (en) | 2013-01-15 |
| JP5363535B2 (en) | 2013-12-11 |
| TW201307919A (en) | 2013-02-16 |
| TWI545357B (en) | 2016-08-11 |
| JP2013016387A (en) | 2013-01-24 |
| CN202720354U (en) | 2013-02-06 |
| CN102866453A (en) | 2013-01-09 |
| EP2544033A1 (en) | 2013-01-09 |
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